1. Field
The present disclosure relates to systems and methods for guiding flight vehicles, and in particular to a system and method for guiding unmanned flight vehicles in the absence of global navigation information.
2. Description of the Related Art
Unmanned aerial vehicles (UAVs) are known in the art. UAVs are typically manually controlled by an remote user or operator who may view aspects of a UAV's flight using cameras installed on the UAV that provide images through downlink telemetry. Navigating such UAVs from a starting position to one or more waypoints typically requires an operator to have specific knowledge of the UAV's flight, including such aspects as starting location, the UAV's current location, waypoint locations, and so on. Automation may be used to fly the UAV from waypoint to waypoint, or to fly the UAV along a particular flight route.
Typically, such navigation is accomplished or at least aided by the use of global navigation systems such as the global positioning system (GPS). Such systems allow the UAV to determine it's location in inertial space to a high degree of accuracy.
However, the information from such global navigation systems is not always available, and may be lost during flight. For example, it is not unusual to lose a signal from a GPS satellite, thus significantly degrading accuracy of the location estimate or rendering it altogether useless. Inertial sensors on-board the UAV may allow UAV to determine it's position to reasonable accuracy over the short term, for example, using dead-reckoning techniques. But such estimates degrade rapidly over time.
What is needed is a system and method that permits UAVs to maneuver without position drift in the absence of global navigation information. A system and method that addresses this need is describe herein.